System and method for faulting to return air sensor

ABSTRACT

A system faults to a return air sensor integrated within a heating, ventilation, and air conditioning (HVAC) unit. The system transmits a signal to a remote sensor. The system determines that a return signal is not received from the remote sensor. The system obtains a temperature reading from the return air sensor. The system determines whether the temperature reading satisfies a temperature setting stored in the memory. In response to determining that the temperature reading does not satisfy the temperature setting, the system enables heating or cooling of the HVAC unit until the temperature setting is satisfied. In response to determining that the temperature reading satisfies the temperature setting, the system disables heating or cooling of the HVAC unit.

CROSS REFERENCE TO RELATED APPLICATION(S)

This application claims the benefit of U.S. Provisional Application Ser.No. 62/817,827, entitled “SYSTEM AND METHOD FOR FAULTING TO RETURN AIRSENSOR” and filed on Mar. 13, 2019, which is expressly incorporated byreference herein in its entirety.

FIELD

The present disclosure generally relates to control of heating,ventilation, and air conditioning (HVAC) systems, and more specificallyto systems and methods for faulting to a return air temperature sensor.

BACKGROUND

Generally, HVAC systems rely on network connectivity and wireless orwired sensors to operate without a formal thermostat. Thus, an HVACsystem can power up and power down based on readings from the sensorsand user defined setpoint information for a temperature and/or ahumidity level. Users can program setpoint information on their mobiledevices via a user interface in many advanced HVAC systems. However, insome cases, the remote sensor may fail or the HVAC system may be unableto communicate with the sensor.

In this situation, the HVAC system must still continue to heat or coolthe building (e.g., a house), but cannot operate without baseinformation regarding the current conditions inside a particularbuilding. In prior configurations, a thermostat provided conditioninginformation and allowed users to identify a setpoint. Furthermore,conventional thermostats were typically wired, so lost connections wererather uncommon. However, with the elimination of a thermostat, whennetwork connectivity is lost, or communication with the remote sensorsare lost, the HVAC system cannot function properly.

Therefore, there is a need for systems and methods that allowuninterrupted heating or cooling even in the event that one or moresensors within a building are unavailable.

SUMMARY

The following presents a simplified summary of one or more aspects inorder to provide a basic understanding of such aspects. This summary isnot an extensive overview of all contemplated aspects, and is intendedto neither identify key or critical elements of all aspects nordelineate the scope of any or all aspects. Its sole purpose is topresent some concepts of one or more aspects in a simplified form as aprelude to the more detailed description that is presented later.

The present disclosure provides temperature control systems,apparatuses, and methods.

In an aspect, a system for faulting to a return air sensor integratedwithin a heating, ventilation, and air conditioning (HVAC) unit includesa memory configured to store a set of instructions; and a processorcoupled with the memory and configured to execute the instructions. Theprocessor is configured to transmit a signal to a remote sensor. Theprocessor is further configured to determine that a return signal is notreceived from the remote sensor. The processor is further configured toobtain a temperature reading from the return air sensor. The processoris further configured to determine whether the temperature readingsatisfies a temperature setting stored in the memory. The processor isfurther configured to, in response to determining that the temperaturereading does not satisfy the temperature setting, enable heating orcooling of the HVAC unit until the temperature setting is satisfied. Theprocessor is further configured to, in response to determining that thetemperature reading satisfies temperature setting, disable heating orcooling of the HVAC unit.

In another aspect, a method for faulting to a return air sensorintegrated within a heating, ventilation, and air conditioning (HVAC)unit is provided. The method includes transmitting a signal to a remotesensor. The method further includes determining that a return signal isnot received from the remote sensor. The method further includesobtaining a temperature reading from the return air sensor. The methodfurther includes determining whether the temperature reading satisfies atemperature setting. The method further includes, in response todetermining that the temperature reading does not satisfy thetemperature setting, enabling heating or cooling of the HVAC unit untilthe temperature setting is satisfied. The method further includes, inresponse to determining that the temperature reading satisfies thetemperature setting, disabling heating or cooling of the HVAC unit.

In a further aspect, a non-transitory computer-readable medium isprovided. The non-transitory computer-readable medium storesinstructions that, when executed by a processor, cause the processor tofault to a return air sensor integrated within a heating, ventilation,and air conditioning (HVAC) unit. The processor is configured totransmit a signal to a remote sensor. The processor is furtherconfigured to determine that a return signal is not received from theremote sensor. The processor is further configured to obtain atemperature reading from the return air sensor. The processor is furtherconfigured to determine whether the temperature reading satisfies atemperature setting. The processor is further configured to, in responseto determining that the temperature reading does not satisfy thetemperature setting, enabling heating or cooling of the HVAC unit untilthe temperature setting is satisfied. The processor is furtherconfigured to, in response to determining that the temperature readingsatisfies the temperature setting, disabling heating or cooling of theHVAC unit.

To the accomplishment of the foregoing and related ends, the one or moreaspects comprise the features hereinafter fully described andparticularly pointed out in the claims. The following description andthe annexed drawings set forth in detail certain illustrative featuresof the one or more aspects. These features are indicative, however, ofbut a few of the various ways in which the principles of various aspectsmay be employed, and this description is intended to include all suchaspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an example of an HVAC system according toaspects of the present disclosure.

FIG. 2 is a flow diagram for an example method of defaulting to a returnair temperature sensor, according to aspects of the present disclosure.

FIG. 3 is a block diagram of an example controller according to aspectsof the present disclosure.

FIG. 4 is a block diagram of an example mobile device according toaspects of the present disclosure.

DETAILED DESCRIPTION

Various aspects of the disclosure are now described with reference tothe drawings, wherein like reference numerals are used to refer to likeelements throughout. In the following description, for purposes ofexplanation, numerous specific details are set forth in order to promotea thorough understanding of one or more aspects of the disclosure. Itmay be evident in some or all instances, however, that any aspectsdescribed below can be practiced without adopting the specific designdetails described below. In other instances, well-known structures anddevices are shown in block diagram form in order to facilitatedescription of one or more aspects. The following presents a simplifiedsummary of one or more aspects of the disclosure in order to provide abasic understanding thereof.

Referring to FIG. 1 , an HVAC system 100 for a building 10 is disclosed.The HVAC system 100 may include an HVAC unit 110 configured to controlan ambient condition of the one or more rooms of the building 10 basedon information from one or more sensors 150 and a remote user device160. In an example, an ambient condition may be a temperature or ahumidity level. As shown by FIG. 1 , the HVAC unit 110 may be externalto the building 10. In an aspect, one or more components (e.g., airconditioning (A/C) unit 112, furnace 114, blower 116, communicationscomponent 130, or controller 140) may be located in different locationsincluding inside the building 10. The building may be a home, office orany other structure that includes uses an HVAC system for controllingone or more ambient conditions of the structure.

In an aspect, the HVAC system 100 may include supply ducts 120 andreturn ducts 124 installed within the building 10 and coupled with theHVAC unit 110. The supply ducts 120 may supply air to the building 10,and the return ducts 124 may return air from the building 10. The supplyducts 120 may receive supply air through one or more of intakes 128 thatprovide outside air to the HVAC system 100 and/or may recycle return airfrom the return ducts 124. The supply ducts 120 may output the supplyair at one or more of the rooms of the building 10 via one or moresupply vents 122. The return ducts 124 may receive return air from thebuilding 10 via the return ducts 124 to balance air within the building10. The return air may be input into the return ducts 124 via one ormore return vents 126. In one aspect, one or more return air sensor(s)125 may be located within the return air duct 124, external to thebuilding 10, though in some configurations, the one or more return airsensor(s) 125 may be located in the building 10 within the return airduct 124 also. In FIG. 1 , the return air sensor 125 is integratedwithin the HVAC unit 110, e.g., is located inside the return ducts 124within the HVAC unit 110, but alternative locations are alsocontemplated herein. The return air sensor 125 measures the temperatureor other settings such as humidity or the like of the air returning fromthe building 10 through the return duct 124.

The HVAC unit 110 may include one or more of an A/C unit 112, a furnace114, a blower 116, a humidifier/dehumidifier 118, or any other component(e.g., heat pump, not shown) for adjusting an ambient condition of aroom of the building 10. The A/C unit 112 may be configured to cool thesupply air by passing the supply air through or around one or morecooled pipes (e.g., chiller pipes) to lower a temperature of the supplyair. The furnace 114 may be configured to warm the supply air by passingthe supply air through or around one or more warmed pipes (e.g., heatingcoils) to raise a temperature of the supply air. The blower 116 may beconfigured to blow the supply air through the supply ducts 120 to thebuilding 10 and pull the return air from the building 10.

The HVAC unit 110 may also include a communications component 130configured to communicate with the one or more sensors 150 and/or theremote user device 160. In an aspect, the communications component 130may communicate with the one or more sensors 150 and/or the remote userdevice 160 via one or more communications links 132. In an example, thecommunications component 130 may include one or more antennas,processors, modems, radio frequency components, and/or circuitry forcommunicating with the sensor 150 and/or the remote user device 160. Theone or more communications links 132 may be wired or wirelesscommunication links.

The HVAC system 100 may also include the one or more sensors 150 locatedwithin one or more rooms of the building 10 and/or within or near thesupply vents 122. One or more sensors 150 may be configured to detect anambient condition such as a temperature or a humidity level of the roomwhere the sensor 150 is located, or even occupancy of the room (using,e.g., optical beam interruption for recognizing movement or the like).Each of the sensors 150 may provide sensor information 131 to the HVACunit 110. Examples of a sensor 150 may include a temperature sensor, ahumidity sensor, or any sensor configured to detect an ambient conditionof one or more rooms of the building 10.

The HVAC system 100 may also include the remote user device 160configured to communicate with the HVAC unit 110. The remote user device180 may include an HVAC application 162 configured to display, adjust,and store setpoint information (“info”) 164 indicating desired usersettings for one or more rooms of the building 10. In an example, thesetpoint information 164 may include temperature settings 166 indicatingone or more desired temperatures (e.g., minimum and/or maximum roomtemperatures) for one or more rooms of the building and/or humiditysettings 188 indicating a desired humidity level for one or more roomsof the building 10. The remote user device 160 may provide the setpointinformation 164 to the HVAC unit 110. Examples of a remote user device160 may include a mobile device, a cellular phone, a smart phone, apersonal digital assistant (PDA), a smart speaker, a home assistant, awireless modem, a wireless communication device, a handheld device, atablet computer, a laptop computer, a cordless phone, a smart watch, anentertainment device, an Internet of Things (IoT) device, or any devicecapable of communicating with the HVAC unit 110. A smart speaker mayinclude, for example, an Echo® device available from Amazon, Inc. ofSeattle, Wash., a Google Home® device available from Google, Inc. ofMountain View, Calif., or other similar devices. The HVAC application162 may include a voice interface that response to voice commands.

The HVAC unit 110 may also include a controller 140 configured tocontrol the A/C unit 112, the furnace 114, and the blower 116 based onthe sensor information 131 received from the one or more sensors 150 andthe setpoint information 164 received from the remote user device 160.The controller may communicate with the communications component 130,the A/C unit 112, the furnace 114, and/or the blower 116 via acommunications bus 134. The controller 140 may include logic todetermine when to initiate the blower 116 along with one of the A/C unit112 or the furnace 114 based on the sensor information 131 and thesetpoint information 164. The controller 140 may also include logic todetermine a time and/or a speed to run the blower 116 along with a timeor power level to run one of the A/C unit 112 or the furnace 114 basedon the sensor information 131 and the setpoint information 164.

The controller 140 may further comprise an operation control component142 to perform the logic of the controller 140, the operation controlcomponent 142 comprising a monitoring component 144, a system initiator146 and a sensor default component 152. The controller 140, in someinstances, may be unable to communicate with the one or more remotesensor(s) 150. In this case, in order to continue uninterruptedoperation of the HVAC unit 110, the controller 140 may rely on thesensor default component 152, a component of the operation controlcomponent 142 to default to reading temperatures from the return airsensor 125 for temperature and/or humidity readings. The sensor defaultcomponent 152 determines whether a return signal is received from theone or more remote sensors 150, using for example, the monitoringcomponent 144 that receives readings via the sensor information (“info”)receiver 148.

In some aspects, the controller 140 waits a predetermined period of time(e.g., approximately thirty seconds to one minute) with no communicationprior to using the return air sensor 125 for temperature readings. Insome aspects, the sensor default component 152 may flag the absence of areturn signal from the one or more remote sensors 150 and issue awarning to a user of the HVAC unit 110 that communication is lost withthe one or more remote sensors 150. The warning may be issued on a userinterface 304 (shown in FIG. 3 ) associated with the HVAC unit, and/orsent as an alert to the user's mobile device(s) 160, using thecommunications component 130. Additionally, the warning may be displayedon the external warning indicator 302 (shown in FIG. 3 ) of the HVACunit 110. In some aspects of the present disclosure, the warning oralert may be an email, text message or any other type of notification,for example a notification associated with an HVAC application 162 onthe mobile device(s) 160.

In some aspects, the sensor default component 152 may use a comparer 149to compare a reading obtained from the return air sensor 125 with thesetpoint information 164. If the reading from the return air sensor 125does not satisfy the temperature settings 166, the system initiator 146will start or stop one or more components of the HVAC unit 110, e.g.,the furnace 114, the A/C 112, the blower 116, etc., until the conditionsspecified in the temperature settings 166 are satisfied. If the readingfrom the return air sensor 125 is equal to or within the minimum andmaximum temperature specified in the settings 166, the sensor defaultcomponent 152 does not initiate the blower 116.

In one non-limiting aspect, for example, when the HVAC unit 110 isconfigured/set for providing heating functionality (e.g., duringwinter), if the reading from the return air sensor 125 is less than acorresponding minimum temperature setting specified in the temperaturesettings 166, the system initiator 146 may start the furnace 114 and theblower 116 to circulate heated air into the building 10 to reduce thereading returned from the return air sensor 125 to meet the temperaturesettings 166. For example, in an aspect, the system initiator 146 mayoperate the furnace 114 and the blower 116 until the reading from thereturn air sensor 125 is greater than or equal to a correspondingmaximum temperature setting specified in the temperature settings 166.

In another non-limiting aspect, for example, when the HVAC unit 110 isconfigured/set for providing cooling functionality (e.g., duringsummer), if the reading from the return air sensor 125 is greater than acorresponding maximum temperature specified in the temperature settings166, the system initiator 146 may start the A/C 112 and the blower 116to circulate cooled air into the building 10 to reduce the readingreturned from the return air sensor 125 to meet the temperature settings166. For example, in an aspect, the system initiator 146 may operate theA/C 112 and the blower 116 until the reading from the return air sensor125 is less than or equal to a corresponding minimum temperature settingspecified in the temperature settings 166.

FIG. 3 shows further detail regarding the controller 140, including auser interface 304 along with a warning indicator 306 that is enabledwhen the monitoring component 144 determines that communication with theremote sensor(s) 150 is unavailable. Further, FIG. 3 illustrates thatthe controller 140 may include a processor 320 and memory 322, thememory 322 storing, for example, last setpoint information 330 in casenetwork communication is lost along with stage setting(s) 340 thatcontrol various stages of operation of the HVAC unit 110 if it is amulti-stage unit. Further detail regarding the implementation ofcontroller 140 is shown in FIG. 5 .

FIG. 2 is a flow diagram for a method 200 for defaulting to a return airsensor by the HVAC unit 110, where the return air sensor is integratedwithin the HVAC unit 110, in accordance with some aspects of the presentdisclosure. The method 200 may implement the functionality describedherein with reference to FIG. 1 and may be performed by one or morecomponents of the HVAC unit 110 as described herein with reference FIGS.1 and 3 .

The method 200 begins at 202, where the method 200 may includedetermining whether a network connection is available to the network theHVAC unit 110 may connect to. If the connection is available, the method200 proceeds to 204. However, if it is detected that the connection isunavailable, the method 200 proceeds to 208, described below, where thereturn air sensor is used to control the HVAC unit. For example, one ormore components (e.g., controller 140, processor 320, operationcontroller 142 or monitoring component 144) of the HVAC unit 110 maydetermine whether the network connection is available or unavailable.

At 204, the method 200 may also include transmitting a signal to one ormore of the remote sensors 150. For example, one or more components(e.g., controller 140, processor 320, operation controller 142 ormonitoring component 144) of the HVAC unit 110 may transmit the signalto one or more remote sensors 150.

At 206, the method 200 may also include determining that a return signalis not received from the one or more remote sensors 150. For example,one or more components (e.g., controller 140, processor 320, operationcontroller 142 or monitoring component 144) of the HVAC unit 110 maydetermine that the return signal is not received. In some aspects, thecomponent waits a predetermined period of time (e.g., thirty seconds toone minute, though this is configurable or preset) prior to continuingwith method 200. In some aspects, the component may flag the absence ofa return signal from the one or more remote sensors 150 and issue awarning to a user of the HVAC unit 110 that communication is lost withthe one or more remote sensors 150. The warning may be issued on a userinterface 304 associated with the HVAC unit, and/or sent as anotification to the user's mobile device(s) 160. Additionally, thewarning may be displayed on the external warning indicator 302 of theHVAC unit 110. In some aspects of the present disclosure, the warningmay be an email, text message or any other type of notification, forexample a notification associated with an HVAC application 162 on themobile device(s) 160.

At 208, the method 200 may also include obtaining a temperature readingfrom a return air temperature sensor (e.g., return air sensor 125integrated within the HVAC unit 110 as shown in FIG. 1 ) as a valuerepresentative of the temperature inside the house. For example, one ormore components (e.g., controller 140, processor 320, operationcontroller 142 or monitoring component 144) of the HVAC unit 110 mayobtain the temperature reading from the return air sensor 125. In someaspects, a significant amount of time may have passed since the blower116 of the HVAC unit 110 has been off. Therefore readings from thereturn air sensor 125 may not be fully representative of the airtemperature inside the building 10. Further, the return air sensor 125may be located external to the building 10 and may be influenced byexternal temperatures. Therefore, in this aspect, prior to obtaining areading from the return air sensor 125, the component may determine thatthe HVAC unit 110 is in an off cycle (e.g., the blower 116 is off) for apredetermined period of time and enable one or more fans of the blower116 of the HVAC unit 110 to circulate air from the respect unit into thebuilding 10 by powering up the blower 116. In some aspects, the air maybe recirculated for a predetermined period of time. Then, when severalcycles of air have flowed in and returned to the HVAC unit 110 via thereturn air duct 124 (i.e., circulated) or a predetermined amount of timehas passed (e.g., five minutes), readings from the return air sensor 125may be significantly more representative of temperatures inside thebuilding 10. Thus, after the air circulates for several cycles, thecomponent may then obtain a temperature reading from the return airsensor 125 before continuing with the method 200.

At 210, the method 200 may also include determining whether the obtainedreadings satisfy a temperature setting specified in the last setpointinformation 330 stored in the memory 322 of the controller 140. Forexample, one or more components (e.g., controller 140, processor 320,operation controller 142 or monitoring component 144) of the HVAC unit110 may compare the obtained temperature with a last setpointinformation 330 stored in the controller 140. In some aspects, thetemperature outside of the house may be significantly different than thetemperature inside of the house and may affect the return air sensor 125that is generally also located outside the building 10 within the returnair duct 124 near the HVAC unit 110. In this instance, it may beadvantageous to, prior to comparing the obtained temperature, obtainambient temperature information if it is available. For example, ambienttemperature information may be obtained by ambient air temperaturesensors (not shown) located outside the HVAC unit 110 or elsewhereoutside the building 10. In other aspects, external temperatureinformation may be obtained through the Internet through a weatherservice or the like. Once the external temperature is received, thereading obtained from the return air sensor 125 may be offset by theexternal temperature reading.

If at 210, the reading from the return air sensor 125 is equal to orwithin the minimum and maximum temperatures specified in the temperaturesettings 166, the sensor default component 152 does not initiate theblower 116 and the method 200 returns to 202. However, in response todetermining that the obtained reading does not satisfy the conditionsspecified in the temperature settings 166, the method 200 proceeds to212.

At 212, the method 200 may also include enabling heating or cooling ofthe HVAC unit 110. For example, one or more components (e.g., controller140, processor 320, operation controller 142 or monitoring component144) of the HVAC unit 110 may enable the heating or cooling of the HVACunit 110, as described above with reference to FIG. 1 . For example, inone non-limiting aspect, when the HVAC unit 110 is configured/set forproviding heating functionality (e.g., during winter), if the readingfrom the return air sensor 125 is less than a corresponding minimumtemperature setting specified in the temperature settings 166, thesystem initiator 146 may start the furnace 114 and the blower 116 tocirculate heated air into the building 10 until the reading returnedfrom the return air sensor 125 meets the temperature settings 166. Forexample, in an aspect, the system initiator 146 may operate the furnace114 and the blower 116 until the reading from the return air sensor 125is greater than or equal to a corresponding maximum temperature settingspecified in the temperature settings 166. In another non-limitingaspect, for example, when the HVAC unit 110 is configured/set forproviding cooling functionality (e.g., during summer), if the readingfrom the return air sensor 125 is greater than a corresponding maximumtemperature setting specified in the temperature settings 166, thesystem initiator 146 may start the A/C 112 and the blower 116 tocirculate cooled air into the building 10 until the reading returnedfrom the return air sensor 125 meets the temperature settings 166. Forexample, in an aspect, the system initiator 146 may operate the A/C 112and the blower 116 until the reading from the return air sensor 125 isless than or equal to a corresponding minimum temperature settingspecified in the temperature settings 166.

Once the reading from the return sensor 125 comes within a particularthreshold value of the temperature settings 166, the method 200 mayreturn to 202, operating periodically until return signals are received.

Though not shown in FIG. 3 , after the setpoint in the setpointinformation 164 is reached, the controller 140 may continuously detectwhether communications with the one or more remote sensors 150 haveresumed. If communications have resumed, the HVAC unit 110 operatesaccording to readings from the one or more remote sensors 150 instead ofthe return air sensor 125. Alternatively, if all of the one or moreremote sensors 150 are still unavailable, the method 200 restarts at202. In some aspects, the controller 140 faults to the return airtemperature sensor when a predetermined threshold number (e.g., 50%, oraccording to a desired configuration) of remote sensors 150 isunavailable.

By way of example, an element, or any portion of an element, or anycombination of elements (e.g., the controller 142 or other components ofthe HVAC system 100) may be implemented as a “processing system” thatincludes one or more processors. Examples of processors includemicroprocessors, microcontrollers, graphics processing units (GPUs),central processing units (CPUs), application processors, digital signalprocessors (DSPs), reduced instruction set computing (RISC) processors,systems on a chip (SoC), baseband processors, field programmable gatearrays (FPGAs), programmable logic devices (PLDs), state machines, gatedlogic, discrete hardware circuits, and other suitable hardwareconfigured to perform the various functionality described throughoutthis disclosure. One or more processors in the processing system mayexecute software. Software shall be construed broadly to meaninstructions, instruction sets, code, code segments, program code,programs, subprograms, software components, applications, softwareapplications, software packages, routines, subroutines, objects,executables, threads of execution, procedures, functions, etc., whetherreferred to as software, firmware, middleware, microcode, hardwaredescription language, or otherwise.

Accordingly, in one or more example aspects, the functions described maybe implemented in hardware, software, or any combination thereof. Ifimplemented in software, the functions may be stored on or encoded asone or more instructions or code on a computer-readable medium.Computer-readable media includes computer storage media. Storage mediamay be any available media that can be accessed by a computer. By way ofexample, and not limitation, such computer-readable media can comprise arandom-access memory (RAM), a read-only memory (ROM), an electricallyerasable programmable ROM (EEPROM), optical disk storage, magnetic diskstorage, other magnetic storage devices, combinations of theaforementioned types of computer-readable media, or any other mediumthat can be used to store computer executable code in the form ofinstructions or data structures that can be accessed by a computer.

The invention claimed is:
 1. A system for faulting to a return airsensor integrated within a heating, ventilation, and air conditioning(HVAC) unit configured to operate using a remote sensor, the systemcomprising: a memory configured to store instructions; and a processorcoupled with the memory and configured to execute the instructions,wherein the processor is configured to: determine whether a networkconfigured to enable the HVAC unit to communicatively couple to theremote sensor is available; in response to determining that the networkis unavailable, obtain a temperature reading from a return air sensor;determine whether the temperature reading satisfies a temperaturesetting stored in the memory; in response to determining that thetemperature reading does not satisfy the temperature setting, enableheating or cooling of the HVAC unit until the temperature setting issatisfied; and in response to determining that the temperature readingsatisfies the temperature setting, disable heating or cooling of theHVAC unit.
 2. The system of claim 1, wherein the processor is furtherconfigured to: determine that the HVAC unit is in an off cycle for afirst predetermined period of time; circulate air from the HVAC unitinto a building by enabling a blower of the HVAC unit; and obtain thetemperature reading from the return air sensor after enabling the blowerof the HVAC unit to circulate air from the HVAC unit into the building.3. The system of claim 2, wherein the processor is further configured toenable the blower to circulate the air for a second predetermined periodof time or a predetermined number of cycles.
 4. The system of claim 1,wherein the processor is further configured to: in response todetermining the network is available, transmit a signal to the remotesensor, wherein the remote sensor is separate from a thermostat; andissue a warning to indicate that communication is lost with the remotesensor in response to an absence of a return signal from the remotesensor.
 5. The system of claim 4, wherein the processor is furtherconfigured to: determine that communication is lost with the remotesensor if the return signal is not received from the remote sensor aftera predetermined amount of time.
 6. The system of claim 5, wherein thepredetermined amount of time is substantially equal to thirty seconds.7. The system of claim 1, wherein the processor is further configuredto: detect communication has resumed with the remote sensor; and operatethe HVAC unit using the remote sensor.
 8. The system of claim 1, whereinthe processor is further configured to: enable a blower prior toobtaining the temperature reading from the return air sensor; and waitfor a predetermined number of air cycles or a predetermined period oftime before obtaining the temperature reading.
 9. The system of claim 1,wherein the processor is further configured to: obtain an outsidetemperature reading; offset the temperature reading from the return airsensor based on the outside temperature reading to provide an offsettemperature reading; determine whether the offset temperature readingsatisfies the temperature setting; in response to determining that theoffset temperature reading does not satisfy the temperature setting,enable heating or cooling of the HVAC unit until the temperature settingis satisfied; and in response to determining that the offset temperaturereading satisfies the temperature setting, disable heating or cooling ofthe HVAC unit.
 10. The system of claim 1, wherein the return air sensoris located inside a return duct within the HVAC unit.
 11. The system ofclaim 1, wherein the processor is further configured to: in response todetermining that the network is available, transmit a signal to theremote sensor, wherein the remote sensor is separate from a thermostat;determine that a return signal is not received from the remote sensor;and use the return air sensor to control the HVAC unit.
 12. A method forfaulting to a return air sensor integrated within a heating,ventilation, and air conditioning (HVAC) unit, wherein the HVAC unit isconfigured to communicatively couple to a remote sensor via a network,the method comprising: in response to determining that the network isavailable, transmitting a signal from an HVAC unit controller to theremote sensor, wherein the remote sensor is not associated with athermostat; determining that a return signal is not received from theremote sensor; determining that the HVAC unit is in an off cycle for afirst predetermined period of time; circulating air from the HVAC unitinto a building by enabling a blower of the HVAC unit; obtaining atemperature reading from the return air sensor integrated within theHVAC unit after enabling the blower of the HVAC unit to circulate airfrom the HVAC unit into the building; determining whether thetemperature reading satisfies a temperature setting; in response todetermining that the temperature reading does not satisfy thetemperature setting, enabling heating or cooling of the HVAC unit untilthe temperature setting is satisfied; and in response to determiningthat the temperature reading satisfies the temperature setting,disabling heating or cooling of the HVAC unit.
 13. The method of claim12, wherein circulating air from the HVAC unit into the building byenabling the blower of the HVAC unit comprises circulating the air for asecond predetermined period of time or a predetermined number of cycles.14. The method of claim 12, further comprising: issuing a warning toindicate that communication is lost with the remote sensor in responseto an absence of the return signal from the remote sensor.
 15. Themethod of claim 12, further comprising: determining that communicationis lost with the remote sensor if the return signal is not receivedafter a predetermined amount of time.
 16. The method of claim 15,wherein the predetermined amount of time is substantially equal tothirty seconds.
 17. The method of claim 12, further comprising:detecting whether the network to which the HVAC unit is configured toconnect to is unavailable; and in response to determining that thenetwork is unavailable, using the return air sensor to control the HVACunit.
 18. The method of claim 12, further comprising: detectingcommunication has resumed with the remote sensor; and operating the HVACunit using the remote sensor.
 19. The method of claim 12, furthercomprising: waiting for a predetermined number of air cycles or a secondpredetermined period of time before obtaining the temperature readingafter enabling the blower of the HVAC unit.
 20. The method of claim 12,further comprising: obtaining an outside temperature reading; offsettingthe temperature reading from the return air sensor based on the outsidetemperature reading to provide an offset temperature reading;determining whether the offset temperature reading satisfies thetemperature setting; in response to determining that the offsettemperature reading does not satisfy the temperature setting, enablingheating or cooling of the HVAC unit until the temperature setting issatisfied; and in response to determining that the offset temperaturereading satisfies the temperature setting, disabling heating or coolingof the HVAC unit.
 21. The method of claim 12, wherein the return airsensor is located inside a return duct within the HVAC unit.
 22. Anon-transitory computer-readable medium storing instructions that, whenexecuted by a processor, cause the processor to fault to a return airsensor integrated within a heating, ventilation, and air conditioning(HVAC) unit and to: determine whether a network configured to enable theHVAC unit to communicatively couple to a remote sensor is available,wherein the remote sensor is independent of a thermostat; and inresponse to determining that the network is unavailable: obtain atemperature reading from the return air sensor; obtain an outsidetemperature reading; offset the temperature reading from the return airsensor based on the outside temperature reading to provide an offsettemperature reading; determine whether the offset temperature readingsatisfies a temperature setting; in response to determining that theoffset temperature reading does not satisfy the temperature setting,enable heating or cooling of the HVAC unit until the temperature settingis satisfied; and in response to determining that the offset temperaturereading satisfies the temperature setting, disable heating or cooling ofthe HVAC unit.
 23. The non-transitory computer-readable medium of claim22, wherein the instructions, when executed by the processor, cause theprocessor to: in response to determining that the network is available:transmit a signal to the remote sensor, wherein the remote sensor isseparate from a thermostat; determine that a return signal is notreceived from the remote sensor; and use the return air sensor tocontrol the HVAC unit.